A monoclonal antibody-linked immunoassay for hemoglobin H disease.

A murine monoclonal antibody (mAb) was generated that recognizes hemoglobin (Hb) H, the tetrameric form (beta 4) of human beta-globin chains. The antibody beta 4-1 (gamma 1, kappa) does not react with Hbs A, F, Bart's, or isolated beta chains, indicating that the antibody recognizes an epitope comprised of multiple beta chains. A simple, rapid, and sensitive enzyme immunoassay was established to detect and quantitate Hb H in hemolysates from subjects with Hb H disease. The delta globin level in these patients was also measured using the monoclonal antibody delta-1, which is specific for delta chains of Hb A2. With these assays, 20 hemolysates from subjects with Hb H disease' ten from normal adults and ten from newborn babies were analyzed. The percent of Hb H ranged from 1.5% to 25% in Hb H patients. There was a significant average reduction (32%) in delta chains in these samples as compared with the normal average adult value. The decreased expression of alpha chains thus results in a reduction of the levels of normal Hbs A and A2 and accumulation of beta 4, causing Hb H disease.